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[Keyword] LIBRA(207hit)

201-207hit(207hit)

  • EMI Dipole Antenna Factors

    Akira SUGIURA  Takao MORIKAWA  Teruo TEJIMA  Hiroshi MASUZAWA  

     
    INVITED PAPER

      Vol:
    E78-B No:2
      Page(s):
    134-139

    Theoretical and experimental investigations of dipole antenna factors were carried out with special interest in their height patterns, since difference between them is a main cause of disagreement in EMI measurement results obtained with different antennas types. Antenna factors were expressed by matrix representation and their dependence on antenna dimensions and balun construction were numerically evaluated with the moment method. Those analyses revealed that antenna dimensions and balun characteristics have little effect on antenna factor height patterns. Slight influence was observed only at frequencies around 30MHz, when an antenna was placed less than 1.5m above a metal ground plane.

  • A Simple Adapter De-Embedding Method in the Six-Port Calibration Process Using a Scalar Analyzer

    Toshiyuki YAKABE  Hatsuo YABE  

     
    PAPER

      Vol:
    E77-C No:6
      Page(s):
    925-929

    A simple adapter de-embedding method is presented in a six-port calibration process using only one sliding load and one standard short. Adapter de-embedding is performed to extract the S-parameters of the adapter from the six-port system parameters. The concept of this method is based on the relations between the S-parameters and the Fourier coefficients of the periodic return loss of the adapter. To complete the de-embedding procedure, there are two measurement steps: one is return loss measurement with the sliding load, and the other, sidearm power measurement with the standard short. Using these measured values, unique solutions of the S-parameters are determined. A computer-controlled six-port with 2.4 mm coaxial-type connector was designed for calibration using a waveguide-type sliding load over the frequency range of 8.5-12.0 GHz. Through experiments, the adapter for joining two unlike connector types was measured. Then the reflection coefficients of the adapter with the sliding load measured by the calibrated six-port and those calculated from the S-parameters were compared with each other. As a result, an overall good agreement with standard deviation of less than 0.1% was found at all setting frequencies. One of the main features of the method is that the S-prameters of a two-port as well as the system parameters of a six-port can be determined by means of simple scalar measurement.

  • Adaptive Signal Processing for Optimal Transmission in Mobile Radio Communications

    Hiroshi SUZUKI  

     
    INVITED PAPER

      Vol:
    E77-B No:5
      Page(s):
    535-544

    This paper reviews recent progress in adaptive signal processing techniques for digital mobile radio communications. In Radio Signal Processing (RSP) , digital signal processing is becoming more important because it makes it relatively easy to develop sophisticated adaptive processing techniques, Adaptive signal processing is especially important for carrier signal processing in RSP. Its main objective is to realize optimal or near-optimal radio signal transmission. Application environments of adaptive signal processing in mobile radio are clarified. Adaptive equalization is discussed in detail with the focus on adaptive MLSE based on the blind algorithm. Demodulation performance examples obtained by simulations and experiments are introduced, which demonstrates the recent advances in this field. Next, new trends in adaptive array processing, interference cancelling, and orthogonalization processing are reviewed. Finally, the three automatic calibration techniques that are based on adaptive signal processing are described for realizing high precision transmission devices.

  • Calibration of Linear CCD Cameras Used in the Detection of the Position of the Light Spot

    Toyohiko HAYASHI  Rika KUSUMI  Michio MIYAKAWA  

     
    PAPER-Image Processing, Computer Graphics and Pattern Recognition

      Vol:
    E76-D No:8
      Page(s):
    912-918

    This paper presents a technique by which any linear CCD camera, be it one with lens distortions, or even one with misaligned lens and CCD, may be calibrated to obtain optimum performance characteristics. The camera-image formation model is described as a polynomial expression, which provides the line-of-sight flat-beam, including the target light-spot. The coefficients of the expression, which are referred to as camera parameters, can be estimated using the linear least-squares technique, in order to minimize the discrepancy between the reference points and the model-driven flat-beam. This technique requires, however, that a rough estimate of camera orientation, as well as a number of reference points, are provided. Experiments employing both computer simulations and actual CCD equipment certified that the model proposed can accurately describe the system, and that the parameter estimation is robust against noise.

  • A Timing Calibration Technique for High-Speed Memory Test

    Mitsuhiro HAMADA  Yasumasa NISHIMURA  Mitsutaka NIIRO  

     
    PAPER

      Vol:
    E75-C No:11
      Page(s):
    1377-1382

    This paper describes a new timing calibration method for IC testers that uses a Timing Calibration Device (TCD). The TCD is a chip fabricated using the same process the device to be tested. Since the TCD has the same assignment pins as the LSI memory device under test (called the "MUT"), it enables an IC tester to evaluate the timing accuracy at the input/output terminal of MUT. The block-select-access time of a 1 K ECL RAM, which is less than 3.0 nanoseconds, has been accurately measured using this device. A timing-calibration subsystem is proposed for IC testers as an application of the TCD. Such a device would achieve precise measurement of high-speed LSI memory devices.

  • An Active Reflector for SAR Calibration Having a Frequency Shift Capability

    Masaharu FUJITA  

     
    LETTER-Radio Communication

      Vol:
    E75-B No:8
      Page(s):
    791-793

    This letter proposes an active reflector for calibrating a synthetic aperture radar (SAR), in which the frequency of a received SAR signal is shifted by a certain amount and then it is retransmitted to the SAR. The frequency shift causes a shift of the reflector SAR image in an azimuth direction relative to its background. This function would allow to enhance a signal-to-clutter ratio of the reflector image by moving it onto a radiometrically dark background, and hence it would be of value for SAR calibration even in a narrow test site. The theory, design and development are described briefly.

  • LIBRA: Automatic Performance-Driven Layout for Analog LSIs

    Tomohiko OHTSUKA  Hiroaki KUNIEDA  Mineo KANEKO  

     
    PAPER

      Vol:
    E75-C No:3
      Page(s):
    312-321

    This paper describes a new approach towards the performance-driven layout for analog LSIs. Based on our approach, we developed an automatic performance-driven layout system LIBRA. The performance-driven layout has an advantage that numerical evaluations of performance requirements may exactly specify layout requirements so that a better layout result will be expected with regard to both the size and the performances. As the first step to the final goal, we only concern with the DC characteristics of analog circuits affected by the placement and routing. First of all, LIBRA performs the sensitivity analysis with respect to process parameters and wire parasitics, which are major causes for DC performance deviations of analog LSIs, so as to describe every perfomance deviation by its first order approximation. Based on the estimations of those performance deviations, LIBRA designs the placement of devices. The placement approach here is the simulated annealing method driven by their circuit performance specification. The routing of inter-cell wires is performed according to the priority of the larger total wire sensitivities in the net by the maze router. Then, the simple compaction eliminates the empty space as much as possible. After that, the power lines optimization is performed so as to minimize the ferformance deviations. Finally, an advantage of the performance improvement by our approach is demonstrated by showing a layout result of a practical bipolar circuit and its excellent performance evaluations.

201-207hit(207hit)